Compartmentalized fluid storage



Julyzw,v 1968 M. STEDFELD i 3,394,556

Y COMPRTMENTALIZED FLUID STORAGE Filed Dec. 19, 1966 I N VEN TOR.

' BY Haw/mf. ffedf/J Q www ATTORNEY United States Patent O 3,394,556 COMPARTMENTALIZED FLUID STORAGE Rowland L. Stedfeld, Indianapolis, Ind., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed Dec. 19, 1966, Ser. No. 602,704 Claims. (Cl. 62-45) ABSTRACT OF THE DISCLOSURE A system involving a fl-uid filled flexible compartmentalized tube and a -tube rupturing and fluid collection device for the controlled, sequential release of that fluid. The tube passes through a collection vessel having a rupturing tool inside for successively releasing the fluid from each individual compartment of a continuous chain of compartments fed through the vessel.

Many highly volatile, normally gaseous, flammable and/or noxious substances, at stand-ard temperatures and pressures, such as ammonia, chlorine (C12), butane, etc. are stored as liquids and have peculiar storage requirements owing to the care with which they must be handled. The uncontrolled escape of large quantities of these materials, incident to the destruction or rupture of conventional storage devices, is undesirable. Nonetheless, the requirement for the use of such chemicals is still great. Hence, for example, an automobile powered yby a Li/LiCl/Cl2 fuel cell has a requirement for liquid C12 storage. Under the normal operating conditions of such a vehicle, a variety of situations occur which can damage the C12 storage system. Many of the conventionally used pressure vessels are not desir-able in such applications, owing to the possibility of the mass escape of the C12, were the vessel to ru-pture or be punctured.

It is, therefore, an object of my invention to provide a new and improved means for storing volatile and flammable or noxious liquids and dispensing them at a r-ate commensurate with the needs of the device in which they are to be used.

It is a further object to provide an improved storage and dispensing system for a fuel cell reactant which eliminates the possibility of in-advertently or accidentally dumping the entire reactant supply into the surrounding environment.

Other objects, features and advantages of the inventi-on will ybecome more apparent from the following description of a preferred embodiment thereof and from the drawing in which FIGURE l shows a sectional View of a storage and dispensing device of this invention.

Briefly stated, my invention comprehends encapsulating a highly volatile, flammable and/or noxious liquid in an inte-rconnected chain yof relatively small ampoule-like containers, storing the thus encapsulated liquid until it is needed, and' then passing the chain of containers through an ampoule-rupturing and fluid collection device which sequentially ruptures each container and releases the liquid contained into a closed environment.

The series of ampoule-like containers are conveniently formed by intermittently sealing, as by heat, a continuous tube of plastic which has been initially filled with the liquid. The thus formed continuous chain of containers is fed' through a rupturing and collection device which comprises essentially a closed vessel having an appropriate tool, such as a knife edge, positioned so as to sequentially rupture the containers as they pass through the vessel.

My invention can also be used to store and supply a gas for a system which, in the case of an accident, would not release all its contained gas but rather only a limited portion thereof. The compartmentalized tube can be filled 3,394,556 Patented July 30, 1968 with a gas and continuously fed into a pressure vessel where the individual compartments are opened and the gas released. Preferably, however, the gas is stored as a liquid which is released in the pressure vessel, -where it vaporizes -to produce the desired gas pressure. Heating means may be employed to accelerate vap'orization and pressure control in the vessel.

Prior to entry into the collection vessel, the compartmentalized tube may be conveniently stored in an unpressurized container, e.g., as by coiling about an enclosed reel which is refrigerated or not, as needed. In my storage and supply system, the collection vessel itself may be quite small. Because the collection vessel is small, it may conveniently be of the heavy wall type to make it virtually indestructible. Hence, because of my invention, the sys-tem is permitted to have the benefits of the heavierwalled, stronger pressure vessel without suffering the weight and bulk penalties normally associ-ated with larger versions yof this heavier construction. Moreover, even if the collection vessel or any portion of the unused compartmentalized tube is ruptured, it releases only a small portion of the liquid contained.

FIGURE l shows an assembly made in accordance with the invention with a portion of a continuous flexible chain 14 of individual interconnected liquid containers 17 passing through a rupture and collection device 1. This assembly is designed for use in conjunction with the storing and dispensing of liquid C12 for a Li/LiC1/C12 fuel cell (not shown). It comprises a pressure vessel having a wall 1.0 defining a Huid collection chamber having inlet and outlet passages 12 and 13 respectively for the entrance and exit of the compartmentalized liquid storage tube 14. A roller 15, is located so as to effectively frictionlessly guide -the tube 14 through the vessel. A blade 16 is l0- cated downstream of the inlet 12 so as to sequentially rupture the successive compartments of the incoming compartmentalized tube 14. In passing through the input and output passages 12 and 13 respectively, lthe tube 14 engages seals 18. The seals 18 are preferably comprised of Teflon (FEP) hollow O-rings. The term Teflon (FEP) is a trademark owned by E. I. du Pont de Nemours and specifies a high molecular weight copolymer of tetrau'oroethylene and hexauoropropylene. The seals effectively prevent the pressurized gas in the vessel from blowing by the sliding joints between the tube 14 and the passages 12 and 13. Several such seals are required to insure that no gas escapes when one of the seals is adjacent a pinched lportion 11 of the tube 14. These seals also have suicient resiliency as to allow substantial conformity to the youtside diameter of tube 14 as it slides through the passages. Prior to the emergence of tube 14 from the vessel 10, any lunvaporized chlorine is wiped from its surface by means of flexible wipers 19. These wipers 19 may also conveniently be comprised of Teflon. The ruptured tube 14 is drawn through the vessel by a friction drive means 20, or the like. The drive means has an adjustable rate 'of speed, and hence can control the rate at which the C12 is fed to the vessel, Threaded hollow stud 23 is adapted to be connected to the supply conduit for the chlorine electrode of the fuel cell. Gasification of the liquid chlorine in the vessel may be accelerated, and the C12 vapor pressure in the system increased by the application of heat to the vessel. Herein, heating coils 22 are provided for this purpose. The heating coils 22 are imbedded in insula-tion 21. With appropriate controls, the speed of the friction drive means 20 and the temperature of the vessel can be varied according to the demand of the fuel cell.

For storing of chlorine, I prefer to use a Teon (FEP) tube having a 1 inch inner diameter and a wall thickness of 0.066 inch. Such a tube can withstand 330 p.s.i.g. internal pressure and need not be refrigerated to contain liquid chlorine under normal conditions. For a Li/LiCl/Cl2 fuel cell having a mission requiring about 200 lbs. of liquid C12, a volume of 4550 cubic inches of storage space is required. When employing the aforementioned l inch ID tube, about 481 feet is required. Obviously, many other combinations of tube size, Wall thickness, and length might also be employed to satisfy these same requirements, as long as the tube chosen is able to withstand the internal pressures required. Of course, if lower storage temperatures are used, the tube strength can be reduced.

Once the choice of tubes has been made, it is filled with liquid. An example of one technique for filling the tube is to invert a liquid C12 storage tank, under proper conditions of temperature and pressure such as to maintain the C12 in the liquid state, and to let it drain into one end of the tube. By holding the other end of the tube at a height equal to the height of the liquid level in the inverted storage tank, the tube will fill completely. After the tube is lled completely, each end of the tube is clamped shut. The thus filled tube is then compartmentalized by any of a variety of techniques. This may be done, for example, by heat sealing in a manner similar to that disclosed by Singer 2,508,197 or Flax 2,940,230. A preferred process for compartmentalizing the C12 utilizes a device which applies several pinching fingers to the tube, which fingers isolate the respective compartments and provide a pinched or flattened region of the tube which is then acted upon by a heat sealing tool. While heat sealing is preferred, any method such as banding and/or plugging the tube between each compartment is also acceptable, so long as the technique employed is compatible with the system in which the tube is to be employed.

While I have disclosed my invention with reference to certain specific examples thereof, I do not intend to be limited thereby except as defined by the appended claims.

I claim: l

1. A system for the storage and controlled release of highly volatile fluids comprising an elongated, continuously connected chain of storage containers for said fluid, a collection vessel for receiving the contents of said containers, means for passing said chain of containers through said collection vessel and means in said vessel for sequentially releasing the contents of said containers in said vessel.

2. The system as claimed in claim 1 wherein said chain of fluid storage containers is a compartmentalized tube.

3. The system as claimed in claim 1 wherein said chain of storage containers is a compartmentalized plastic tube, said collection vessel has a fluid lreceiving chamber, a tube input passage to said chamber, a tube output passage from said chamber, and a fluid output passage from said chamber, and said means for releasing the contents of said containers comprises tool means for sequentially rupturing said uid containers.

4. The system as claimed in claim 3 wherein said tool means has a knife edge positioned near said input passage to sequentially rupture each compartment of said tube as it passes into said vessel.

5. A system for the storage yand controlled release of a halogen comprising a compartmentalized polymeric uorocarbon tube, a pressure vessel having a fluid collection chamber, a tube input passa-ge, a tube output passage, and a halogen output passage, means for moving said compartmentalized tube through said vessel, and a tube yrupturing means positioned near said tube input passage to sequentially rupture said tube as it passes through said vessel.

6. The system as claimed in claim 5 wherein said halogen is chlorine and said fluorocarbon is a copolymer of tetrafluoroethylene and hexafluoropropylene.

7. The system as claimed in claim 5 wherein said means for moving said compartmentalized tube through said vessel includes a friction drive apparatus outside said closed vessel.

8. A fuel cell system comprising a fuel cell having at least one highly volatile uid reactant, a storage system for said fluid reactant, and means communicating said storage system with said cell wherein said storage system comprises an elongated, continuously connected chain of storage containers for said reactant, a collection vessel for receiving the contents of said containers, means for passing said chain of containers through said vessel, and means in said vessel for releasing the contents of said containers in said vessel as they pass through it.

9. The system as claimed in claim 8 wherein said fuel cell is an alkali metal/halide/halogen cell, said chain of storage containers is a compartmentalized polymeric uorocarbon tube, said collection vessel has a fluid collection chamber, a tube input passage and a tube output passage, and has a reactant output passage communicat ing with said cell.

10. The system claimed in claim 9 wherein said alkali metal is lithium, said halide is principally lithium chloride, said halogen is chlorine, said fluorocarbon is a copolymer of tetraffuoroethylene and hexafiuoropropylene, and said means for releasing said contents of said containers is a knife edge Ipositioned near said tube input passage to sequentially rupture said tube yas it passes into said vessel.

References Cited UNITED STATES PATENTS 1,383,270 6/1921 Henning 62-294 2,773,358 12/ 1956 Palmer et al. 62-294 3,298,194 1/ 1967 Hutchinson 62-294 LLOYD L. KING, Primary Examiner, 

